import random
lst=[]
lst=[i for i in range(1,100)]
random.shuffle(lst)
for i in range(10,101):
    lst.append(i)
for item in lst:
    if item%2==0:
        x = random.choice(lst)
        y = random.choice(lst)
        answer_1=x-y
        if answer_1<0:
            while True:
                x = random.choice(lst)
                y = random.choice(lst)
                answer_1 = x - y
                if answer_1>0:
                    break
                elif answer_1<0:
                    continue
        print(x, end='-')
        print(y, end='')
        m = eval(input('='))
        if m == x - y:
            print('答对了')
        else:
            while True:
                print('答错了，再试一遍')
                print(x, end='-')
                print(y, end='')
                m = eval(input('='))
                if m == x-y:
                    print('答对了')
                    break
                else:
                    continue
        print('-' * 20)
    elif item%2==1:
        x = random.choice(lst)
        y = random.choice(lst)
        print(x, end='+')
        print(y, end='')
        m = eval(input('='))
        if m == x+y:
            print('答对了')
        else:
            while True:
                print('答错了，再试一遍')
                print(x, end='+')
                print(y, end='')
                m = eval(input('='))
                if m == x+y:
                    print('答对了')
                    break
                else:
                    continue
        print('-' * 20)

